Effect of the freezing conditions and microwave thawing power on the stability of cefuroxime in dextrose 5% infusion polyolefin bags at 4 degrees C

BACKGROUND: Intravenous cefuroxime sodium solution could be prepared in advance by a centralized hospital pharmacy service to improve safety and time management. OBJECTIVE: To investigate the effect of freezing and microwave thawing on the solution stability of cefuroxime. METHODS: Cefuroxime 1.5 g in 100 mL of dextrose 5% in polyolefin bags was frozen individually (group A) or in one package (group B) for 98 days at -20 degrees C. The solutions were then thawed using microwaves at 270 (light cycle) or 800 watts (hard cycle) and stored at 4 degrees C. The cefuroxime concentration was measured by HPLC. Visual inspection was performed and pH was measured at that time. Stability of the solution was defined as a concentration remaining superior to 90% of the initial concentration by regression analysis. RESULTS: No color change or precipitation in the solutions was observed. In group A, stability was at least 23 and 21 days after light and hard cycle thawing, respectively. In group B, stability was at least 21 and 18 days, respectively, with the pH increasing without affecting chromatographic parameters. CONCLUSIONS: The optimal conditions for advance preparation of a solution containing cefuroxime 1.5% in dextrose 5% may be freezing of individual containers followed by a light cycle of microwave thawing.     

Seventy-two-hour stability of Taxol in 5% dextrose or 0.9% sodium chloride in Viaflo, Freeflex, Ecoflac and Macoflex N non-PVC bags

BACKGROUND AND OBJECTIVES: Taxol (paclitaxel), is an antimicrotubule agent widely prescribed for the treatment of many tumoral diseases. Taxol must be used in non-polyvinyl chloride bags, diluted to concentrations of 0.3-1.2 mg/mL in 5% dextrose or in 0.9% sodium chloride. Under these conditions, Taxol is chemically and physically stable for 27 h at 25 degrees C. The aim of the study was to evaluate the 72-h stability of Taxol under common clinical use conditions. METHODS: Taxol was diluted with 5% dextrose and 0.9% sodium chloride to final concentrations of 0.3 and 1.2 mg/mL in four polyolefin bags (Viaflo, Freeflex, Ecoflac and Macoflex N). Taxol-stability, was assessed by turbidimetry and by high-performance liquid chromatography using solutions stored in the dark, over 72 h at +4 degrees C. RESULTS: No haze, turbidity, or precipitate was observed. Paclitaxel concentration remained above 95% of the initial value whatever the solvent or container used. CONCLUSION: Paclitaxel at 0.3 and 1.2 mg/mL in 5% dextrose and in 0.9% sodium chloride is stable in Viaflo, Freeflex, Ecoflac and Macoflex N non-PVC bags for 72 h in the dark at +4 degrees C. The longer stability should make the use of Taxol in clinical practice easier.     

Stability and compatibility of doxofylline with phentolamine mesilate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion

What is know and objective: The use of extemporaneously prepared admixtures of drugs must be supported by documentation of their chemical stability. The objective was to assess the physical compatibility and the chemical stability of doxofylline with phentolamine mesilate in 0·9% sodium chloride or 5% dextrose injection for intravenous infusion. Methods: Total volumes of 20 and 1 mL of doxofylline solution and phentolamine mesilate solution, respectively, were added to 250 mL polyolefin bags containing 5% dextrose injection or 0·9% sodium chloride injection. Bags were stored for 24 h at 20–25 °C. Chemical compatibility was measures with high‐performance liquid chromatography, and physical compatibility was determined visually. Results: The samples were clear and colourless when viewed in normal fluorescent room light. The pH value and particulate content of the admixtures exhibited little change. The retentions of the initial concentration of doxofylline and phentolamine mesilate in the admixtures were within 97–105%. Doxofylline and phentolamine mesilate were stable in 5% dextrose injection or in 0·9% sodium chloride for up to 24 h at 20–25 °C. What is new and conclusion: Doxofylline and phentolamine mesilate mixed in both 5% dextrose injection and 0·9% sodium chloride injection in 250 mL multilayer polyolefin bags at concentrations of 0·74 mg/mL and 36·9 μg/mL, respectively, were stable for up to 24 h at 20–25 °C.     

Continuous infusion of calcium gluconate in 5% albumin is safe and prevents most hypocalcemic reactions during therapeutic plasma exchange

While therapeutic plasma exchanges (TPEs) performed with 5% albumin are considered safe, concerns regarding venous access and hypocalcemic toxicity remain. We reviewed the frequency of complications during TPEs performed with 5% albumin supplemented with calcium gluconate and potassium chloride for a 5 year period in our institution. Eighty-four adult patients (46 males and 38 females) underwent 581 plasma exchanges during the study period. The most common indications were myasthenia gravis (37%), acute inflammatory demyelinating polyradiculoneuropathy (31%), and chronic inflammatory demyelinating polyneuropathy (13%). All procedures used 2.2% ACD-A delivered at a calculated average rate of 0.26 mg/kg/min, which led to a mean dose of citrate per TPE of 2.18 +/- 0.48 g or 27.8 +/- 5.24 mg/kg of body weight. Venous access difficulties occurred in 85 procedures (14.6%), but most TPEs were completed successfully. Hypotension and citrate toxicity were seen in <5% of the TPEs and were mostly reversible. Only 17 exchanges (3%) had to be aborted because of the loss of venous access (n = 9), hypocalcemic toxicity (n = 3), hypotension (n = 2), panic attacks (n = 2), and one atypical reaction due to the interaction with an angiotensin converting enzyme inhibitor. Comparison between pre- and post-TPE potassium levels showed a statistically significant mean decrease of 7%, from 4.1 mequiv/l to 3.8 mequiv/l (P < 0.0001). We attribute the low rate of hypocalcemia to our practice of adding calcium and potassium to the replacement fluid and suggest that this method could become standard of care.     

高效液相色谱法测定注射用奥沙利铂5％葡萄糖注射液中5-羟甲基糠醛的含量

目的采用高效液相色谱法测定注射用奥沙利铂5%葡萄糖注射液中的5-羟甲基糠醛的含量。方法采用高效液相色谱法测定注射用奥沙利铂5%葡萄糖注射液中的5-羟甲基糠醛的含量,用十八烷基键合硅胶色谱柱(型号:Unitary C18;孔径:100A;柱长:250 mm×4.6 mm;直径:5μm),流动相A为0.05 M磷酸二氢钾溶液,流动相B为乙腈,梯度洗脱,流速为1.0 mL/min,检测波长为284 nm,柱温30℃,进样体积20μL。结果5-羟甲基糠醛在0.0997~5.5016μg/mL浓度范围内线性关系良好(r=0.9998),加样回收率为99.18%,RSD为1.42%。结论经方法学验证,高效液相色谱法操作简便、精密度、准确度高,线性关系良好,重现性好,能满足注射用奥沙利铂在5%葡萄糖注射液中5-羟甲基糠醛的含量测定要求,可用于该产品的质量控制。     

A stability indicating assay for a combination of morphine sulphate with levomepromazine hydrochloride used in palliative care

What is known and objective: Morphine is used routinely in clinical practice to manage moderate to severe pain, whereas levomepromazine is commonly used at low doses to manage intractable nausea and vomiting. While it has been reported that an injection combination of morphine sulphate (0·5 mg/mL) and levomepromazine (0·1 mg/mL) was physically compatible, data on the chemical stability of combinations of these drugs has not been reported. Thus, a method was required for the assessment of the stability of morphine sulphate/levomepromazine hydrochloride combinations. Methods: A high‐performance liquid chromatography (HPLC) method was developed to assess the stability of the combinations. The injections were stored at 4 °C in the dark at room temperature under natural light and at 37 °C under artificial lighting. Results and Discussion: Morphine sulphate was stable under all storage conditions, but the degree of degradation of levomepromazine hydrochloride increased as the storage temperature increased. The disappearance of levomepromazine hydrochloride was correlated with the appearance of a sulphoxide degradant. What is new Conclusion: The injection combinations of morphine sulphate and levomepromazine hydrochloride were shown in the current study to have a limited storage life with respect to their levomepromazine hydrochloride content.     

Stability of high-dose insulin in normal saline bags for treatment of calcium channel blocker and beta blocker overdose

Context: High-dose insulin has become a first-line therapy for treating severe calcium channel blocker and beta blocker toxicity. Insulin infusions used to treat other conditions (e.g., diabetic ketoacidosis) may be used, but this may lead to pulmonary compromise due to fluid volume overload. An obvious solution would be to use a more concentrated insulin infusion; however, data describing the stability of insulin in polyvinyl chloride bags at concentrations >1 unit/mL are not readily available.

Objective: To determine the stability of insulin at 16 units/mL in 0.9% saline solution.

Materials and methods: Eight-hundred units of regular insulin (8?mL from a stock vial containing 100 units/mL) were added to 42?mL of 0.9% saline solution in a polyvinyl chloride bag to make a final concentration of 16 units/mL. Two bags were stored at 4?°C (refrigerated) and two at 25?°C (room temperature). Samples were withdrawn and tested for insulin concentration periodically over 14 days.

Results: Concentrated regular insulin in a polyvinyl chloride bag remained within 90% of equilibrium concentration at all time points, indicating the 16 units/mL concentration was sufficiently stable both refrigerated and at room temperature for 14 days.

Discussion: Administration of high-dose insulin can cause fluid volume overload when using traditional insulin formulations. The 16 units/mL concentration allows for the treatment of a patient with severe calcium channel blocker or beta blocker toxicity for a reasonable period of time without administering excessive fluid.

Conclusion: Insulin at a concentration of 16 units/mL is stable for 14 days, the maximum timeframe currently allowed under US Pharmacopeia rules for compounding of sterile preparations. This stability data will allow institutions to issue beyond-use dating for intravenous fluids containing concentrated insulin and used for treating beta blocker and calcium channel blocker toxicity.     

应用CLSI EP5-A2文件评价ADAMSTM A1c HA-8160全自动糖化血红蛋白仪的精密度

目的：对 HA-8160全自动糖化血红蛋白仪进行精密度性能评价。方法按照 CLSI EP5-A2文件要求,利用高值和正常两水平质控品对 HA-8160全自动糖化血红蛋白仪测定糖化血红蛋白（HbA1c）项目的精密度进行评价。结果HA-8160全自动糖化血红蛋白仪测定糖化血红蛋白（HbA1c）项目高值和正常两水平的批内精密度变异系数分别为0．97％和1．45％;批间精密度变异系数分别为0．62％和0．34％;日间精密度变异系数分别为0．63％和0．56％;总精密度变异系数分别为1．31％和1．59％。结论 HA-8160全自动糖化血红蛋白仪测定HbA1C 的精密度能够满足临床检测要求。     

Simultaneous determination of mycophenolate and its metabolite mycophenolate-7-o-glucuronide with an isocratic HPLC-UV-based method in human plasma and stability evaluation

Objectives: Mycophenolic acid (MPA) is an immunosuppressive agent which is commonly used in a fixed dose regime in solid organ transplantation. For clinical trials and therapeutic drug monitoring measuring plasma concentrations is necessary. Also, stability issues have to be addressed.

Methods: We describe an isocratic, RP-based HPLC-UV method for simultaneous determination of MPA and its major metabolite Mycophenolic acid 7-o Glucuronide (MPAG) in human plasma. Pre-analytics included protein precipitation with acetonitrile. The method was validated according to EMA/FDA guidelines. Patient lithium-heparin plasma and blood was used for evaluation of short-term (72?hours at room temperature?=?RT) and long-term stability (2 years at ?80?°C) without acidification.

Results: Linearity was assessed in the concentration range of 0.5–40.0?μg/mL for MPA and 5.0–350.0?μg/mL for MPAG, respectively. For MPA coefficient of variation was <7.0% (lower limit of quantification?=?LLOQ: 10.8%), for MPAG <9.6% (LLOQ: 10.6%). Bias ranged between ?1.9 and?+1.5% for MPA and for MPAG between ?4.3 and ?0.3%. The method showed agreement with a reference method for both analytes. MPA remained stable for 7?h (?1.6 to?+8.4% change to the initial concentration) and MPAG for 24?h (?1.8 to ?11.5% change) at RT in lithium heparin blood. After 2 years of storage at ?80?°C MPA, MPAG concentrations and 95% CIs remained within ±15% of the initial value.

Conclusion: The presented assay is applicable for clinical studies. Blood samples were stable for 7?hours at RT and plasma for 2 years stored at ?80?°C.     

血红蛋白异常对高效液相色谱法检测糖化血红蛋白的影响

目的探讨血红蛋白（Hb）异常对高效液相色法谱检测糖化血红蛋白（HbA1c）的影响。方法使用国内常用的硼酸盐亲和层析高效液相色谱法（PDQ系统）及离子交换层析高效液相色谱法（D-10系统）进行含有不同（梯度）浓度HbF与正常人血液混合的标本的干扰实验及检测40例Hb异常的临床标本中的HbA1c。结果在干扰实验中,D-10系统在HbF在浓度超过40%时,可能无法获得检测结果,当HbF浓度在10%～40%时,结果高于实际值,HbF在浓度低于10%时,结果与实际值相似;PDQ系统在HbF浓度超过40%时,结果可能略低于实际值,HbF浓度低于40%时,可以获得好的结果。在40例Hb异常的临床标本中,D-10系统检测结果明显高于PDQ系统,差异具有统计学意义（P〈0.05）,其中有5例Hb异常总量超过35%的标本在D-10系统中无法获得检测结果,而PDQ检测获得可接受的结果;Hb异常总量低于10%时,两种方法检测结果有较好的一致性（P〉0.05）。结论硼酸盐亲和层析抗Hb异常的干扰能力优于离子交换层析。     

颈动脉粥样硬化超声表现与血浆同型半胱氨酸浓度增高的关系研究

目的:探讨颈动脉内膜-中层增厚及动脉粥样硬化(AS)斑块形成与血浆同型半胱氨酸(Hcy)浓度增高的关系。方法:选取87例首发急性脑血栓形成住院病人作为病例组,平均(66.13±12.54)岁;选取80例同期眼科和耳鼻喉科住院病人作为对照组,平均(64.94±11.26)岁。应用Sequia 512彩超仪对病例组55例、对照组66例双侧颈总、颈内、颈外动脉进行扫查,测量颈动脉前后壁内膜-中层厚度(IMT),观察有无AS斑块形成及其位置,计算颈动脉狭窄程度。应用高效液相色谱-荧光法(HPLC-FD)测定两组所有病例的血浆Hcy浓度。并同时进行空腹血糖(FBS)、糖化血红蛋白(HbA1C)、肝肾生化、血脂、血压及体重指数(BMI)的测定。比较两组AS危险因素。结果:病例组和对照组平均空腹血浆Hcy浓度分别为(15.28±4.33)μmol/L和(11.32±3.86)μmol/L。病例组血浆Hcy浓度较对照组高且差异具统计学意义(P<0.001),病例组和对照组血浆Hcy升高者分别占31%和6.3%,差异具统计学意义(P<0.001)。病例组与对照组左、右颈动脉IMT及AS斑块发生率差异均有统计学意义(P<0.05)。比较两组AS危险因素,经Logistic回归分析,发现血浆Hcy浓度、收缩压、BMI是脑血栓形成的危险因素,在校正了高血压和肥胖后,血浆Hcy浓度升高是脑血栓形成的独立危险因素。结论:血浆Hcy浓度升高可导致AS,与颈动脉粥样硬化有关。     

低钙透析液对CAPD患者钙磷代谢的影响

目的观察低钙腹膜透析液（1．25mmol／L）（LCD）与标准钙离子浓度（1．75mmol／L）的腹膜透析液（SCD）对CAPD患者钙磷代谢的影响。方法选择血钙高于正常或高钙磷乘积的CAPD患者57例，随机分成两组：SCD组24例；LCD组33例。观察两组患者血钙、磷、镁、全段甲状旁腺激素（iPTH）和皮肤瘙痒情况的变化，及不良反应。观察时间为6个月。结果共53例完成6个月的观察，其中SCD22例，LCD31例。6个月后两组的血钙水平均有所下降，但LCD组血钙水平较前明显下降（P〈0．05），SCD组无统计学意义（P〉0．05）；SCD组患者的血清磷、镁及钙磷乘积无明显变化，而LCD组上述指标明显下降，与SCD组比较具有统计学意义（P〈0．05）；与SCD相比，LCD组的iPTH水平明显升高（P〈0．05）；LCD患者皮肤瘙痒情况有所改善，但无统计学意义（P〉0．05）。观察期间LCD组患者无低血压、低钙抽搐等情况发生。结论低钙腹膜透析液能够较好控制血钙水平，降低血磷，减轻对甲状旁腺的抑制，可能在预防和改善动力缺失性骨病的发生和发展过程中发挥重要的作用。     

微粒色谱法和高效液相色谱法检测糖化血红蛋白的相关性研究

目的分析微粒色谱法和高效液相色谱法在糖化血红蛋白(HbA1c)检测中的相关性和临床符合情况。方法依照美国临床和实验室标准协会(CLSI)的EP9-A2文件要求,每日随机抽取重庆市急救中心门诊或住院患者血液标本8份,连续5d,共采取40份。分别用微粒色谱法和高效液相色谱法测定HbA1c,并对数据进行比较分析。结果对两种方法测定的HbA1c结果进行比对分析,结果表明两检测系统内重复性好,符合相关性实验要求;方法间无离群点存在;线性回归方程为Y=1.088 5 X-0.521 4,相关系数r=0.993,95%置信区间(B^C,low,B^C,high)为(0.019 1,0.181 8),在允许误差(-0.35,0.35)之内,两种方法测定结果无明显差异,不存在有意义的偏倚。结论微粒色谱法和高效液相色谱法可比性高,相关性好,符合临床需求,检验科可根据自身条件,选择适合的测定方法。     

钙剂补充改善献血者柠檬酸盐抗凝剂相关副反应的研究

目的了解不同钙剂补充方式对改善献血者柠檬酸盐抗凝剂相关副反应的效果。方法在获得知情同意后,对22名年龄匹配的志愿者应用自身交叉、安慰剂对照研究模式,在一定的间隔期内分别实施了3次标准化条件下的临床干预方案,A:持续80min,按1.5mg.kg-1.min-1输注柠檬酸盐抗凝剂;B:A+输注前10min口服1.2g钙剂;C:A+静脉输注葡萄糖酸钙100mg/h。在干预实施的同时记录受试者对柠檬酸盐抗凝剂输注的反应,并采集不同观测时间点血样做游离钙离子浓度(iCa2+)检测。结果柠檬酸盐相关副反应主要表现为口唇、面部、肢体麻木、胸闷、头晕、恶心等轻、中度反应;临床干预40、80和干预结束后120min时,A组与C组相比,iCa2+(mmol/L)分别为1.00±0.05vs1.06±0.05、0.94±0.06vs1.04±0.06、1.22±0.05vs1.30±0.05(P<0.01),两组副反应发生率对比为54.55%vs18.18%(P<0.05),而A组vsB组这2项指标的差异无统计学意义(P>0.05);A组中的男性与女性相比,干预终末点iCa2+(mmol/L)为0.98±0.04vs0.90±0.06(P<0.01),副反应发生率为13.64%vs40.91%(P<0.05)。副反应的发生与干预性补钙终末点的iCa2+密切相关(r=-0.52,P=0.01)而与试验对象的体重无关(r=-0.238,P=0.286)。结论本研究模式下,静脉补钙比口服补钙能够更加有效地改善柠檬酸盐所致低钙血症并减少相关副反应的发生;以口服补钙作为预防措施时则需在服用剂量和服用时间上多加考虑。对女性献血者在机采血液前进行常规性的预防性补钙是有益的。     

变异血红蛋白对2种基于HPLC原理的糖化血红蛋白检测系统的影响

目的比较亲和层析-高效液相色谱(AC-HPLC)系统和离子交换-高效液相色谱(IE-HPLC)系统测定血红蛋白(Hb)结构不同的血液样本中HbAlc的结果,评价变异Hb对2种检测系统的影响。方法分别用2种HPLC系统同时检测HbA1c含量在5%~11%、Hb结构正常的血液样本和含有不同浓度胎儿Hb(HbF)的血液样本以及α-地中海贫血(α-MA)和β-地中海贫血(β-MA)患者血液样本中的HbA1c浓度。结果对于Hb结构正常、HbA1c含量在5%~11%的血液样本,2种HPLC检测系统的测定结果差异无统计学意义(P>0.05)。AC-HPLC法不受血液样本中HbF的干扰;若血液样本中HbF的含量超过8.8%,IE-HPLC法测定结果存在一定的偏倚,当HbF含量达70%时甚至无法测出结果。对于α-MA和轻型β-MA患者的血液样本,IE-HPLC法的结果明显高于AC-HPLC法(P<0.01、P<0.05),而重型β-MA患者的样本用IE-HPLC法甚至无法测得结果。结论用IE-HPLC法检测含变异Hb、HbF的样本中的HbA1c,结果可能受干扰;而用AC-HPLC法则不受干扰。     

RP-HPLC法测定人血浆中齐拉西酮质量浓度

目的建立用反相高效液相色谱(RP-HPLC)法测定人血浆中齐拉西酮质量浓度的办法。方法以Acclaim~(TM)12 C_(18)反相柱(250mm×4.6mm,5μm)为色谱柱,流动相为0.2%三乙胺-甲醇(15∶85);流速:1.1mL/min;柱温:35℃;检测波长:230nm,以乙酸乙酯为萃取剂。结果齐拉西酮在8.0~300.0ng/mL质量浓度范围内,其质量浓度与峰面积呈良好线性关系;齐拉西酮低、中、高质量浓度(8.0、80.0、350.0ng/mL)相对回收率均大于95%;提取回收率均大于90%。日内、日间相对标准偏差均低于10%(n=5)。分析方法的检测限为5.0ng/mL;齐拉西酮的曲线方程:Y=1.193 X+0.013,r=0.999 7(n=7)。结论该法灵敏、简单、准确、快速,可用于临床齐拉西酮血药浓度的监测。     

高效液相色谱串联质谱法测定血清非结合雌三醇的前处理研究

目的优化高效液相色谱串联质谱法(LC-MS/MS)测定血清游离雌三醇(uE3)的前处理方法。方法以活性炭吸附血清为研究基质,通过加入已知量的雌三醇(E3)标准品及E3-2-3-4-13 C3内标,在LC-20AD XR高效液相色谱系统和API 5500串联四级杆质谱仪上对E3检测的色谱条件、质谱条件及萃取条件等进行优化。结果色谱条件:选用菲罗门Knietex色谱柱(100.0mm×2.1mm,2.6μm);有机相为甲醇,水相为0.1mmol/L氟化铵水溶液,8min梯度洗脱。质谱条件:选用电喷雾(ESI)负离子模式和多反应监测(MRM)模式分析,选择质荷比(m/z)287→m/z 145作为E3的定量离子对,m/z 287→m/z 171作为定性监测离子对;选择m/z 290→m/z 148作为内标的定量离子对,m/z 290→m/z 174作为定性监测的离子对。萃取条件:萃取剂为正己烷/乙酸乙酯(50/50,v/v),样品与萃取剂的比例为1∶2,萃取率可达85.71%。结论 E3检测的色谱条件、质谱条件、萃取条件已得到全面优化,为后续建立LC-MS/MS测定人血中uE3的参考方法打下良好基础。     

高效液相色谱分析在HbE筛查中的应用价值

目的探讨高效液相色谱分析法在HbE病筛查中的价值。方法应用高效液相色谱分析仪对24 779例样本进行血红蛋白(Hb)分析,HbA2≥11%的样本进行HbE基因检测。结果 24 779例标本中检出129例HbA2≥11%的样本,含量为14.0%～75.2%(27.2%±9.4%)。经基因检测均确诊为HbE病,包括HbE杂合子、HbE/α-珠蛋白生成障碍性贫血、HbE/β-珠蛋白生成障碍性贫血、HbE/α-β-珠蛋白生成障碍性贫血和HbE纯合子,其HbA2含量分别为(26.1±1.3)%、(18.2±1.8)%、(45.9±8.0)%、38.6%和(73.9±1.8)%。经ROC曲线分析HbA2筛查HbE的临界值为11.7%。结论高效液相色谱不仅能有效地筛查HbE病,还可以通过HbA2含量区分HbE病突变类型及其复合珠蛋白生成障碍性贫血的类型,是筛查HbE病的有效方法。     

Effect of acute bile acid pool depletion on total and ionized calcium concentrations in human bile*

Abstract. Although calcium salts are important components of gallstones, there are few data on the total and ionized calcium content of human bile. Therefore, in 14 fasting T-tube patients studied 7–11 days after cholecystectomy, we measured bile flow, bile acid [BA], total [Ca_TOt] and free ionized [Ca⁺⁺] calcium concentrations, in 20–30 min bile collections during acute BA pool depletion induced by 6–8 h of continuous bile drainage. During washout of the BA pool there were parallel falls in bile flow, BA output and total calcium output (correlation coefficients ranging from 0.59 to 0.99; P< 0.02–0.001). In 12 of the 14 patients, [Ca_TOT] also fell (from 1.84 ± 0.29 to l.32 ± 0.34 mmol L^-1) in parallel with [BA] (from 34.0 ± 14.0 to 8.2 ± 8.0 mmol L^-1; r= 0.75–0.98; P<0.005). In contrast, biliary [Ca⁺⁺] remained virtually unchanged. These data suggest that the BAs are linked to the bound, rather than to the free, ionized, fraction of biliary calcium, which is consistent with in vivo calcium binding by BAs. A model is proposed in which BA-induced biliary calcium secretion results from (i) bile acid-induced water flow via solvent drag; and (ii) calcium binding in the bile canaliculus by bile acids, which induces paracellular diffusion of Ca⁺⁺, thereby maintaining [Ca⁺⁺] independent of [BA].     

长期使用Ca~+1.25mmol/L透析液对维持性血液透析患者矿物质代谢的影响

目的观察长期应用钙离子浓度为1.25mmol/L的低钙透析液(low calcium dialysate,LCa D)对维持性血液透析患者(maintained hemodialysis,MHD)矿物质代谢的影响。方法选择进行血液透析治疗3个月以上的慢性肾衰竭患者50例,分别观察应用低钙透析液3,6,9个月后钙磷,甲状旁腺激素的变化。结果应用1.25mmol/L的低钙透析液透析后不同血钙水平的组别及不同i PTH水平的组别血钙浓度均有明显下降。整体观察血磷在低钙透析3,6个月时无明显改变,9个月时有明显下降(P0.05)。血i PTH多在低钙透析3个月时无明显改变,应用至6,9个月后有明显升高(P0.05)。结论低钙透析可降低部分血液透析患者血钙水平,使得血磷更易控制;但同时可能加重SHPT,需同时合理使用钙剂及活性维生素D。